Legality question for an entrepreneur.?

I would like to build custom grow boxes for small indoor plant grows. It would be something like storage cabinets with lights, input and output fans for air flow and temp control, Mylar film on interior walls for light reflection, thermometer, light timer, and rubber seals to keep light from showing from the exterior. From the outside it would basically look like an ordinary storage container. It would be sold as an indoor grow box for your plants and herbs but who am i kidding? I know most will use it for growing cannabis. Would it will legal to build these and sell them on craigslist or a website without having a visit from the police? PS This is a serious question and I don't want any dumb answers about knowing what i'm really trying to do and its wrong from some moral standpoint. I just want to know if its legal? I live in Texas by the way.